All the data that a forecaster requires is available on the
Advanced Weather Interactive Processing System (AWIPS)–
our mainframe computer system. On
AWIPS, current observations, satellite, radar, upper air profiles, and computer
models (numerical simulations of atmospheric variables) are stored for analysis
and interrogation. The system is highly
flexible, allowing forecasters to create and store personalized procedures, so
that data can be readily recalled in a familiar format.
Although a planar view is most popular, it is
also possible to view data in cross section or time vs. height as well.
AWIPS also provides forecasters the ability
to overlay various fields on one image, which greatly facilitates in analysis
and comparison.

Step 2: Grid Construction

Forecast
grids are created and edited
using the Graphical Forecast Editor [GFE]. A typical GFE interface
window can be seen to the left.

Each grey rectangle on the left side of the frame represents a gridded weather element. The
rectangle in yellow is the “active” grid; that is, it’s
the grid seen on the right half of the screen.

Changes can be made to this
field using numerous techniques.
It can be contoured, adjusted up/down, or assigned
a specific value, to name just a few possible actions.
The entire grid can be adjusted at once, or
an edit area can first be selected. An
enlarged view of the top section of the GFE window can be found below.
Most of the controls can be found there or
in
the Edit Actions box to the right.

Rarely do
forecasters start from scratch. Often
adjustments are made from the current set of grids. However, if there is a
computer model of choice, that data is available to import into the
database. Typically, the method used to
construct a grid depends upon the field being edited and forecaster preference.
There are tools and procedures designed to
handle some elements. For instance, once
the maximum and minimum temperatures have been drawn, there is a procedure to
create hourly temperatures. Then, once thedewpoint fields have been finalized, there is a tool to run
to ensure that the dewpoints aren’t higher
than the temperatures. Finally, there’s
another procedure available to create the hourly relative humidity grids.
In this manner, we can facilitate grid
creation while ensuring that the grids are internally consistent.

Throughout this process,
forecasters must collaborate with surrounding offices to ensure a seamless
suite of products.There are two
methods to assist us. Offices are connected to each other using Instant Messaging software.
This allows forecasters from several offices
to discuss the meteorological setup and problems of the day, and arrive
at a
solution. Also, there is an Intersite Coordination Mode in GFE, which allows forecasters
to view the most current grids of surrounding offices, as seen to
the right. Thus, any lingering discrepancies
can be spotted and resolved prior to product issuance.

There
are even grids available to handle watches, warnings, and advisories.
The software within GFE has the ability to create the appropriate text
products, and insert the correct headlines and coding into the remainder
of the
product suite.

Step 3: Forecast Generation

With
the grids complete, the computer’s formatters can be run
to create all forecast products, based on the same database. Although
the products are computer-worded, forecasters have the ability
to tweak wordings for clarity prior to dissemination. The
data is also available via routine channels in numerous forms
for customer use.